Click for Coverage
  • JP Magazine
  • Dirt Sports + Off-Road
  • 4-Wheel & Off-Road
  • Four Wheeler
Subscribe to the Free
Newsletter
X

Traction Does Matter

Posted in How To on March 1, 2000
Share this
From left to right, these are the new Right-Trac and All-Lock lockers and the Silentek silencer replacement kit (all names are trademarked). John Zentmyer, the man who brought us the Lock-Right more than 10 years ago, invented all three. Just like their predecessor, these lockers use the original (open) differential case and therefore can be installed by just about anyone. Each has its own advantages, but the All-Lock is the most intriguing with its unique sprag system. From left to right, these are the new Right-Trac and All-Lock lockers and the Silentek silencer replacement kit (all names are trademarked). John Zentmyer, the man who brought us the Lock-Right more than 10 years ago, invented all three. Just like their predecessor, these lockers use the original (open) differential case and therefore can be installed by just about anyone. Each has its own advantages, but the All-Lock is the most intriguing with its unique sprag system.
The key benefit to the Right-Trac (left) design is the square-cut teeth. Compared to the number of the old Lock-Right’s angled teeth (right), there are also more of them. The latter helps cut down on backlash, while the former eliminates the forces that try to break apart the diff case by spreading it. The key benefit to the Right-Trac (left) design is the square-cut teeth. Compared to the number of the old Lock-Right’s angled teeth (right), there are also more of them. The latter helps cut down on backlash, while the former eliminates the forces that try to break apart the diff case by spreading it.
One advantage of the Right-Trac (right) is that its reverse operation (compared to the Lock-Right) when overriding allows C-clip installation without the need for a large cutout in the coupler gear (as on the Lock-Right on the left). One advantage of the Right-Trac (right) is that its reverse operation (compared to the Lock-Right) when overriding allows C-clip installation without the need for a large cutout in the coupler gear (as on the Lock-Right on the left).
This is a Right-Trac in drive mode. The unit overrides by pulling the drivegear to the center. Notice the unlocking tab that simplifies installation. This is a Right-Trac in drive mode. The unit overrides by pulling the drivegear to the center. Notice the unlocking tab that simplifies installation.
At a glance, the Right-Trac looks similar to the Lock-Right. However, from the specially machined cross-shaft to the entirely redesigned drive mechanism, it’s not. This particular unit, for example, needs no spacer block. At a glance, the Right-Trac looks similar to the Lock-Right. However, from the specially machined cross-shaft to the entirely redesigned drive mechanism, it’s not. This particular unit, for example, needs no spacer block.
An All-Lock consists of only a few pieces. The 30 so-called rollers per side in the sprag clutches are controlled individually by what’s referred to as a control plate, making the unit operate like a ratchet with an infinite number of teeth. In fact, it was a very good 1/4-inch ratchet that inspired John Zentmyer to develop this diff. An All-Lock consists of only a few pieces. The 30 so-called rollers per side in the sprag clutches are controlled individually by what’s referred to as a control plate, making the unit operate like a ratchet with an infinite number of teeth. In fact, it was a very good 1/4-inch ratchet that inspired John Zentmyer to develop this diff.
If you’re familiar with what makes a Lock-Right tick (or click), this photo may explain how the Silentek keeps the unit from making any sounds at all. Not visible in this photo are the fine internal teeth on the blocking ring (below the coupler gear, which has a support plate in place) that is part of the silencer setup. Also different from a regular Lock-Right’s guts is the spacer assembly below. If you’re familiar with what makes a Lock-Right tick (or click), this photo may explain how the Silentek keeps the unit from making any sounds at all. Not visible in this photo are the fine internal teeth on the blocking ring (below the coupler gear, which has a support plate in place) that is part of the silencer setup. Also different from a regular Lock-Right’s guts is the spacer assembly below.
Like the Lock-Right, the All-Lock and Right-Trac (All-Lock shown) install in the original diff case, making home installation easier by eliminating the need to set up the ring-and-pinion gears. Like the Lock-Right, the All-Lock and Right-Trac (All-Lock shown) install in the original diff case, making home installation easier by eliminating the need to set up the ring-and-pinion gears.

Back in January 1990, Four Wheeler magazine introduced the All-Trac locking diff, which later evolved into the Lock-Right, both the brainchild of John Zentmyer. Many trail miles have passed since, but that doesn’t mean the gears in Zentmyer’s head have stopped turning. On the contrary, his company, Traction Matters, now has three new inventions to share with Four Wheeler readers.

First is the Right-Trac, which Zentmyer describes as an improved Lock-Right. Next is the Silentek, a retrofit kit for Lock-Right diffs that’s meant to eliminate the clicking sound that results when cornering. Last but certainly not least, the All-Lock is a completely different approach to locker mechanisms, largely aimed at minimizing the sometimes annoying traits of a locker.

THE RIGHT-TRAC
Primarily, as Zentmyer explains, it’s the square teeth on the Right-Trac that gives it strength. Without any forces trying to spread the diff case, the case effectively becomes stronger than stock, only having to deal with rotational forces. To make the square-tooth design work, a different disengagement design was needed. Drive gears pull together when overriding (going around a corner), which offers the benefit of not needing a relief cut in the teeth for C-clip installations.

From what we saw, assembly appears to be easier since the small parts now go toward the outside, rather than in the center.

THE ALL-LOCK
Using a two-way sprag clutch, the All-Lock is a new approach to the locker world. Sprag clutches are usually found in automatic trannies and helicopter rotors, and they act much like a ratchet but without teeth. No teeth should mean faster reactions, and getting as little backlash as possible should minimize the handling quirks on the street typically associated with lockers going around corners. Since the axle gears effectively multiply the backlash, having only a little to start with should be helpful. There’s about three degrees’ worth in the All-Lock, we’re told, and the unit indeed reacts extremely quickly and operates smoothly, as we observed on an All-Lock–equipped vehicle on a lift. Like the Right-Trac, the All-Lock puts the forces perpendicularly to the axleshafts, so stress on the diff case is reduced.

THE SILENTEK
Not a locking differential but an upgrade kit, the Silentek is made to eliminate the clicking sound of Lock-Rights. Neither the Right-Trac nor the All-Lock clicks in the turns (the All-Lock can’t since there are no gears), but those who dislike the sound of the Lock-Right, new or used, can install the Silentek, which prevents the locking teeth from trying to engage during a turn.

COMING SOON TO AN AXLE NEAR YOU
Four Wheeler was the first magazine to lay eyes on these new products from Traction Matters, and at the time (November 1999), they were not in production. We’re told the All-Lock should be available for GM 12-bolts and Toyota FJ40 Land Cruisers by the time you read this, with the Right-Trac following shortly thereafter. (The popular Dana 44 will be the next target axle.) The Silentek will likely be the last to appear in production form.

Additionally, at this writing, the only scheduled way to purchase any of these products was from Traction Matters directly on the Internet (guess the computer age really is here). For more info, contact Traction Matters at its Web site or ask a friend who’s more in tune with keyboards than wrenches to download the free stuff for you. We suspect that once production is in full swing, you’ll be able to find these Traction Matters pieces at your favorite four-by store.

Sources

Unitrax
Anaheim, CA 92806
800-622-4327
www.gounitrax.com

Connect With Us

Newsletter Sign Up

Subscribe to the Magazine

Browse Articles By Vehicle

See Results